package com.jiayang.hhotel.adapter;

/*
 *  Copyright 2011 Yuri Kanivets
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

import android.database.DataSetObserver;
import android.view.View;
import android.view.ViewGroup;

/**
 * Wheel items adapter interface
 */
public interface WheelViewAdapter {
    /**
     * Gets items count
     *
     * @return the count of wheel items
     */
    public int getItemsCount();

    /**
     * Get a View that displays the data at the specified position in the data
     * set
     *
     * @param index
     *            the item index
     * @param convertView
     *            the old view to reuse if possible
     * @param parent
     *            the parent that this view will eventually be attached to
     * @return the wheel item View
     */
    public View getItem(int index, View convertView, ViewGroup parent);

    /**
     * Get a View that displays an empty wheel item placed before the first or
     * after the last wheel item.
     *
     * @param convertView
     *            the old view to reuse if possible
     * @param parent
     *            the parent that this view will eventually be attached to
     * @return the empty item View
     */
    public View getEmptyItem(View convertView, ViewGroup parent);

    /**
     * Register an observer that is called when changes happen to the data used
     * by this adapter.
     *
     * @param observer
     *            the observer to be registered
     */
    public void registerDataSetObserver(DataSetObserver observer);

    /**
     * Unregister an observer that has previously been registered
     *
     * @param observer
     *            the observer to be unregistered
     */
    void unregisterDataSetObserver(DataSetObserver observer);
}
